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Kerr WT, Brandt C, Ngo LY, Patten A, Cheng JY, Kramer L, French JA. Time to exceed pre-randomization monthly seizure count for perampanel in participants with primary generalized tonic-clonic seizures: A potential clinical end point. Epilepsia 2022; 63:2994-3004. [PMID: 36106379 PMCID: PMC9828687 DOI: 10.1111/epi.17411] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/13/2022] [Accepted: 09/13/2022] [Indexed: 01/12/2023]
Abstract
OBJECTIVE To evaluate the exploratory time to exceed pre-randomization seizure count (T-PSC) in the determination of efficacy of adjunctive perampanel in participants with primary generalized tonic-clonic (PGTC) seizures in generalized-onset epilepsy. METHODS In this multicenter, double-blind study (ClinicalTrials.gov identifier: NCT01393743), participants ≥12 years of age with treatment-resistant idiopathic generalized epilepsy were randomized to receive placebo or adjunctive perampanel (≤8 mg/day) across a 17-week double-blind treatment phase (4-week titration; 13-week maintenance). We evaluated the pre-planned exploratory end point of the T-PSC using a Kaplan-Meier analysis. We also re-evaluated the correspondence of the primary end points of median percent seizure frequency change (MPC) and 50% responder rate (50RR) calculated at T-PSC and at the end of the trial. RESULTS The exploratory end point of median T-PSC on placebo was 43 days and >120 days on perampanel (log-rank p < .001). The primary end points calculated at T-PSC did not differ significantly from the end points at the end of the trial (MPC -31% vs -42% at T-PSC; 50RR 32% vs 51% at T-PSC). After T-PSC was reached, participants had a median (interquartile range) of 5 (3-13) additional seizures on placebo and 5 (2-10) on perampanel. SIGNIFICANCE The exploratory end point of T-PSC demonstrated the effectiveness of perampanel despite a shorter duration of monitoring. The seizures that occurred after T-PSC did not influence the conclusions of the trial; therefore, T-PSC may be a viable alternative to traditional trial end points that reduces the risk to participants.
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Affiliation(s)
- Wesley T. Kerr
- Department of NeurologyUniversity of MichiganAnn ArborMichiganUSA
| | - Christian Brandt
- Bethel Epilepsy CenterUniversity Hospital for EpileptologyBielefeldGermany
| | - Leock Y. Ngo
- Department of NeurologyEisai Inc.NutleyNew JerseyUSA
| | | | | | - Lynn Kramer
- Department of NeurologyEisai Inc.NutleyNew JerseyUSA
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Shi LL, Bresnahan R, Martin-McGill KJ, Dong J, Ni H, Geng J. Felbamate add-on therapy for drug-resistant focal epilepsy. Cochrane Database Syst Rev 2022; 8:CD008295. [PMID: 35914010 PMCID: PMC9342851 DOI: 10.1002/14651858.cd008295.pub6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND This is an updated version of the Cochrane Review first published in 2011, and most recently updated in 2019. Epilepsy is a chronic and disabling neurological disorder, affecting approximately 1% of the population. Up to 30% of people with epilepsy have seizures that are resistant to currently available antiepileptic drugs and require treatment with multiple antiepileptic drugs in combination. Felbamate is a second-generation antiepileptic drug that can be used as add-on therapy to standard antiepileptic drugs. OBJECTIVES To evaluate the efficacy and tolerability of felbamate versus placebo when used as an add-on treatment for people with drug-resistant focal-onset epilepsy. SEARCH METHODS For the latest update, we searched the Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid, 1946 to 13 July 2021) on 15 July 2021. There were no language or time restrictions. We reviewed the reference lists of retrieved studies to search for additional reports of relevant studies. We also contacted the manufacturers of felbamate and experts in the field for information about any unpublished or ongoing studies. SELECTION CRITERIA We searched for randomised placebo-controlled add-on studies of people of any age with drug-resistant focal seizures. The studies could be double-blind, single-blind or unblinded and could be of parallel-group or cross-over design. DATA COLLECTION AND ANALYSIS Two review authors independently selected studies for inclusion and extracted information. In the case of disagreements, a third review author arbitrated. Review authors assessed the following outcomes: 50% or greater reduction in seizure frequency; absolute or percentage reduction in seizure frequency; treatment withdrawal; adverse effects; quality of life. MAIN RESULTS We included four randomised controlled trials, representing a total of 236 participants, in the review. Two trials had parallel-group design, the third had a two-period cross-over design, and the fourth had a three-period cross-over design. We judged all four studies to be at an unclear risk of bias overall. Bias arose from the incomplete reporting of methodological details, the incomplete and selective reporting of outcome data, and from participants having unstable drug regimens during experimental treatment in one trial. Due to significant methodological heterogeneity, clinical heterogeneity and differences in outcome measures, it was not possible to perform a meta-analysis of the extracted data. Only one study reported the outcome of 50% or greater reduction in seizure frequency, whilst three studies reported percentage reduction in seizure frequency compared to placebo. One study claimed an average seizure reduction of 35.8% with add-on felbamate whilst another study claimed a more modest reduction of 4.2%. Both studies reported that seizure frequency increased with add-on placebo and that there was a significant difference in seizure reduction between felbamate and placebo (P = 0.0005 and P = 0.018, respectively). The third study reported a 14% reduction in seizure frequency with add-on felbamate but stated that the difference between treatments was not significant. There were conflicting results regarding treatment withdrawal. One study reported a higher treatment withdrawal for placebo-randomised participants, whereas the other three studies reported higher treatment withdrawal rates for felbamate-randomised participants. Notably, the treatment withdrawal rates for felbamate treatment groups across all four studies remained reasonably low (less than 10%), suggesting that felbamate may be well tolerated. Felbamate-randomised participants most commonly withdrew from treatment due to adverse effects. The adverse effects consistently reported by all four studies were headache, dizziness and nausea. All three adverse effects were reported by 23% to 40% of felbamate-treated participants versus 3% to 15% of placebo-treated participants. We assessed the evidence for all outcomes using GRADE and rated the evidence as very low certainty, meaning that we have little confidence in the findings reported. We mainly downgraded evidence for imprecision due to the narrative synthesis conducted and the low number of events. We stress that the true effect of felbamate could likely be significantly different from that reported in this current review update. AUTHORS' CONCLUSIONS In view of the methodological deficiencies, the limited number of included studies and the differences in outcome measures, we have found no reliable evidence to support the use of felbamate as an add-on therapy in people with drug-resistant focal-onset epilepsy. A large-scale, randomised controlled trial conducted over a longer period of time is required to inform clinical practice.
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Affiliation(s)
- Li Li Shi
- Evidence-based Medicine Center, Medical School of Nantong University, Nantong, China
| | - Rebecca Bresnahan
- Department of Health Data Science, Institute of Population Health, University of Liverpool, Liverpool, UK
| | | | - JianCheng Dong
- Evidence-based Medicine Center, Medical School of Nantong University, Nantong, China
| | - HengJian Ni
- Evidence-based Medicine Center, Medical School of Nantong University, Nantong, China
| | - JinSong Geng
- Evidence-based Medicine Center, Medical School of Nantong University, Nantong, China
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Shi LL, Bresnahan R, Martin‐McGill KJ, Dong J, Ni H, Geng J. Felbamate add-on therapy for drug-resistant focal epilepsy. Cochrane Database Syst Rev 2019; 8:CD008295. [PMID: 31425617 PMCID: PMC6699672 DOI: 10.1002/14651858.cd008295.pub5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND This is an updated version of the Cochrane Review previously published in 2017.Epilepsy is a chronic and disabling neurological disorder, affecting approximately 1% of the population. Up to 30% of people with epilepsy have seizures that are resistant to currently available antiepileptic drugs and require treatment with multiple antiepileptic drugs in combination. Felbamate is a second-generation antiepileptic drug that can be used as add-on therapy to standard antiepileptic drugs. OBJECTIVES To evaluate the efficacy and tolerability of felbamate versus placebo when used as an add-on treatment for people with drug-resistant focal-onset epilepsy. SEARCH METHODS For the latest update we searched the Cochrane Register of Studies (CRS Web), MEDLINE, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP), on 18 December 2018. There were no language or time restrictions. We reviewed the reference lists of retrieved studies to search for additional reports of relevant studies. We also contacted the manufacturers of felbamate and experts in the field for information about any unpublished or ongoing studies. SELECTION CRITERIA We searched for randomised placebo-controlled add-on studies of people of any age with drug-resistant focal seizures. The studies could be double-blind, single-blind or unblinded and could be of parallel-group or cross-over design. DATA COLLECTION AND ANALYSIS Two review authors independently selected studies for inclusion and extracted information. In the case of disagreements, the third review author arbitrated. Review authors assessed the following outcomes: 50% or greater reduction in seizure frequency; absolute or percentage reduction in seizure frequency; treatment withdrawal; adverse effects; quality of life. MAIN RESULTS We included four randomised controlled trials, representing a total of 236 participants, in the review. Two trials had parallel-group design, the third had a two-period cross-over design, and the fourth had a three-period cross-over design. We judged all four studies to be at an unclear risk of bias overall. Bias arose from the incomplete reporting of methodological details, the incomplete and selective reporting of outcome data, and from participants having unstable drug regimens during experimental treatment in one trial. Due to significant methodological heterogeneity, clinical heterogeneity and differences in outcome measures, it was not possible to perform a meta-analysis of the extracted data.Only one study reported the outcome, 50% or greater reduction in seizure frequency, whilst three studies reported percentage reduction in seizure frequency compared to placebo. One study claimed an average seizure reduction of 35.8% with add-on felbamate while another study claimed a more modest reduction of 4.2%. Both studies reported that seizure frequency increased with add-on placebo and that there was a significant difference in seizure reduction between felbamate and placebo (P = 0.0005 and P = 0.018, respectively). The third study reported a 14% reduction in seizure frequency with add-on felbamate but stated that the difference between treatments was not significant. There were conflicting results regarding treatment withdrawal. One study reported a higher treatment withdrawal for placebo-randomised participants, whereas the other three studies reported higher treatment withdrawal rates for felbamate-randomised participants. Notably, the treatment withdrawal rates for felbamate treatment groups across all four studies remained reasonably low (less than 10%), suggesting that felbamate may be well tolerated. Felbamate-randomised participants most commonly withdrew from treatment due to adverse effects. The adverse effects consistently reported by all four studies were: headache, dizziness and nausea. All three adverse effects were reported by 23% to 40% of felbamate-treated participants versus 3% to 15% of placebo-treated participants.We assessed the evidence for all outcomes using GRADE and found it as being very-low certainty, meaning that we have little confidence in the findings reported. We mainly downgraded evidence for imprecision due to the narrative synthesis conducted and the low number of events. We stress that the true effect of felbamate could likely be significantly different from that reported in this current review update. AUTHORS' CONCLUSIONS In view of the methodological deficiencies, the limited number of included studies and the differences in outcome measures, we have found no reliable evidence to support the use of felbamate as an add-on therapy in people with drug-resistant focal-onset epilepsy. A large-scale, randomised controlled trial conducted over a longer period of time is required to inform clinical practice.
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Affiliation(s)
- Li Li Shi
- Evidence‐based Medicine Center, Medical School of Nantong UniversityNantongChina
| | - Rebecca Bresnahan
- Institute of Translational Medicine, University of LiverpoolDepartment of Molecular and Clinical PharmacologyLower LaneLiverpoolUKL9 7LJ
| | - Kirsty J Martin‐McGill
- Institute of Translational Medicine, University of LiverpoolDepartment of Molecular and Clinical PharmacologyLower LaneLiverpoolUKL9 7LJ
- University of ChesterDepartment of Clinical Sciences and NutritionFaculty of Medicine, Dentistry and Life SciencesChesterUK
| | - JianCheng Dong
- Medical School of Nantong UniversityEvidence‐based Medicine Center19 Qixiu RoadNantongJiangsuChina226001
| | - HengJian Ni
- Medical School of Nantong UniversityEvidence‐based Medicine Center19 Qixiu RoadNantongJiangsuChina226001
| | - JinSong Geng
- Medical School of Nantong UniversityEvidence‐based Medicine Center19 Qixiu RoadNantongJiangsuChina226001
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Efficacy of antiepileptic drugs in the adjunctive treatment of refractory partial-onset seizures: Meta-analysis of pivotal trials. Epilepsy Res 2019; 143:120-129. [PMID: 29784458 DOI: 10.1016/j.eplepsyres.2017.10.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 07/14/2017] [Accepted: 10/03/2017] [Indexed: 11/23/2022]
Abstract
OBJECTIVE In the absence of randomized clinical trials (RCTs) assessing the relative efficacy of antiepileptic drugs (AEDs), meta-analyses are useful resources for informing treatment choices. This meta-analysis assesses the relative efficacy and tolerability of AEDs for adjunctive treatment of refractory partial onset seizures (POS). METHODS A systematic literature review was conducted to identify pivotal AED trials serving as the basis for US Food and Drug Administration (FDA) approval. INCLUSION CRITERIA 1) double-blind, placebo-controlled, parallel-group design, with 8- to 14-week maintenance period; 2) enrolled patients ≥16years with refractory POS, including complex partial seizures; 3) study was conducted between 1993 and 2013; and; 4) patients received FDA-approved dosage. Outcomes analyzed: 1) 50% responder rate (≥50% reduction from baseline in seizure frequency); 2) seizure freedom (proportion of seizure-free patients); and 3) discontinuation due to adverse events (AEs). DerSimonian and Laird random-effects model was used to derive odds ratios (OR) and 95% confidence intervals (CI). RESULTS A total of 29 publications for 11 AEDs (eslicarbazepine, ezogabine, gabapentin, lacosamide, levetiracetam, perampanel, pregabalin, tiagabine, topiramate, vigabatrin, and zonisamide) were included in the meta-analysis. Tiagabine 56mg/day (OR 8.82, 95% CI: 2.77-28.11), pregabalin 600mg/day (OR 8.08, 95% CI: 5.45-11.98), and vigabatrin 3000mg/day (OR 6.23, 95% CI: 1.46-26.20) had the highest OR versus placebo of 50% response. The odds of seizure freedom were ≥7 times greater than placebo for levetiracetam 3000mg/day (OR 11.00, 95% CI: 2.08-58.06), vigabatrin 3000mg/day (OR 7.41, 95% CI: 1.31-41.84), and ezogabine 1200mg/day (OR 7.09, 95% CI: 0.36-58.06). Patients were more likely to discontinue any AED (except low-dose pregabalin) than placebo. CONCLUSION In this meta-analysis of >9000 patients, those treated with AEDs were more likely than placebo to achieve seizure response or freedom. Patients receiving pregabalin, tiagabine, and vigabatrin had the highest odds of ≥50% reduction in seizures, and patients receiving ezogabine, levetiracetam, and vigabatrin had the highest odds of seizure freedom.
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Abstract
BACKGROUND This review is an update of a previously published review in the Cochrane Database of Systematic Reviews (Issue 7, 2014) on 'Felbamate as an add-on therapy for refractory epilepsy'. Epilepsy is a chronic and disabling neurologic disorder, affecting approximately 1% of the population. Up to 30% of people with epilepsy have seizures that are resistant to currently available drugs. Felbamate is one of the second-generation antiepileptic drugs and we have assessed its effects as an add-on therapy to standard drugs in this review. OBJECTIVES To evaluate the efficacy and tolerability of felbamate versus placebo when used as an add-on treatment for people with refractory partial-onset epilepsy. SEARCH METHODS For the latest update we searched the Cochrane Epilepsy Specialized Register, CENTRAL, MEDLINE, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform, up to 20 October 2016. There were no language and time restrictions. We reviewed the reference lists of retrieved studies to search for additional reports of relevant studies. We also contacted the manufacturers of felbamate and experts in the field for information about any unpublished or ongoing studies. SELECTION CRITERIA Randomised placebo-controlled add-on studies of people of any age with refractory partial-onset seizures. The studies could be double-blind, single-blind or unblinded and could be of parallel or cross-over design. DATA COLLECTION AND ANALYSIS Two review authors independently selected studies for inclusion and extracted information. We resolved disagreements by discussion. If disagreements persisted, the third review author arbitrated. We assessed the following outcomes: 50% or greater reduction in seizure frequency; absolute or percentage reduction in seizure frequency; treatment withdrawal; adverse effects; quality of life. MAIN RESULTS We included four randomised controlled trials with a total of 236 participants. Two trials were parallel design, the third had a two-period cross-over design, and the fourth had a three-period cross-over design. Two studies were at an unclear risk of bias for random sequence generation and allocation concealment. These two studies did not include any description of their methods for outcome assessment and performance blinding (i.e. participants or doctors). Two studies were at high risk of bias for incomplete outcome data. Due to significant methodological heterogeneity, clinical heterogeneity and differences in outcome measures, it was not possible to perform a meta-analysis of the results. Only one study reported 50% or greater reduction in seizure frequency. One study reported absolute and percentage reduction in seizure frequency compared to placebo, P values were 0.046 and 0.018, respectively. One study reported percentage reduction in seizure frequency compared to placebo, but there were no P values. Adverse effects rates were higher during the felbamate period than the placebo period, particularly headache, nausea and dizziness. AUTHORS' CONCLUSIONS In view of the methodological deficiencies, limited number of individual studies and differences in outcome measures, we have found no reliable evidence to support the use of felbamate as an add-on therapy in people with refractory partial-onset epilepsy. A large-scale, randomised controlled trial conducted over a longer period of time is required to inform clinical practice.
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Affiliation(s)
- Li Li Shi
- Evidence‐based Medicine Center, Medical School of Nantong UniversityNantongChina
| | - JianCheng Dong
- Medical School of Nantong UniversityEvidence‐based Medicine Center19 Qixiu RoadNantongChina226001
| | - HengJian Ni
- Medical School of Nantong UniversityEvidence‐based Medicine Center19 Qixiu RoadNantongChina226001
| | - JinSong Geng
- Medical School of Nantong UniversityEvidence‐based Medicine Center19 Qixiu RoadNantongChina226001
| | - Taixiang Wu
- West China Hospital, Sichuan UniversityChinese Clinical Trial Registry, Chinese Ethics Committee of Registering Clinical TrialsNo. 37, Guo Xue XiangChengduChina610041
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Golyala A, Kwan P. Drug development for refractory epilepsy: The past 25 years and beyond. Seizure 2017; 44:147-156. [DOI: 10.1016/j.seizure.2016.11.022] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 11/30/2016] [Indexed: 01/25/2023] Open
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French JA, Gazzola DM. New generation antiepileptic drugs: what do they offer in terms of improved tolerability and safety? Ther Adv Drug Saf 2014; 2:141-58. [PMID: 25083209 DOI: 10.1177/2042098611411127] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Over the last two decades a total of 11 antiepileptic drugs (AEDs) have been introduced to the US market. Randomized, placebo-controlled trials have yielded information about each drug's efficacy, tolerability, and safety profile; however, few studies have compared the newer generation AEDs directly with the older generation. Comparative studies are not always straightforward in their interpretation, as many characteristics of drugs, both favorable and unfavorable, may not be highlighted by such studies. In general, findings from the literature suggest that the newer generation AEDs (including vigabatrin, felbamate, gabapentin, lamotrigine, tiagabine, topiramate, levetiracetam, oxcarbazepine, zonisamide, pregabalin, rufinamide, and lacosamide) enjoy both improved tolerability and safety compared with older agents such as phenobarbital, phenytoin, carbamazepine, and valproate. This is partially supported by some of the findings of the QSS and the TTA Committee of the American Academy of Neurology (AAN), whose review of four AEDs (gabapentin, lamotrigine, topiramate, and tiagabine) is discussed. Briefly, when compared with carbamazepine, lamotrigine was better tolerated; topiramate adverse events (AEs) were fairly comparable to carbamazepine and valproate; and tiagabine compared with placebo was associated with a higher discontinuation rate due to AEs. The findings of the SANAD trial are also presented; when administered to patients with partial epilepsy, carbamazepine was most likely to fail due to AEs, and lamotrigine and gabapentin were least likely to fail due to AEs. When administered to patients with idiopathic generalized epilepsy, topiramate was most frequently associated with AE-related discontinuation, followed by valproate; and while valproate was the most efficacious drug in this arm of the study, lamotrigine was more tolerable. What makes the SANAD study valuable and somewhat unique is its head-to-head comparison of one drug with another. Such comparative trials are overall lacking for new AEDs, although some conclusions can be drawn from the available data. In the end, however, AED selection must be based on individual patient and drug characteristics.
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Affiliation(s)
- Jacqueline A French
- New York University School of Medicine, NYU Comprehensive Epilepsy Center, 223 East 34th Street, New York, NY 10016, USA
| | - Deana M Gazzola
- New York University School of Medicine, NYU Comprehensive Epilepsy Center, New York, NY, USA
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Abstract
BACKGROUND This review is an update of a previously published review in The Cochrane Database of Systematic Reviews (Issue 1, 2011) on 'Felbamate as an add-on therapy for refractory epilepsy'. Epilepsy is a chronic and disabling neurologic disorder, affecting approximately 1% of the population. Up to 30% of people with epilepsy have seizures that are resistant to currently available drugs. Felbamate is one of the second-generation antiepileptic drugs and its effects as an add-on therapy to standard drugs are assessed in this review. OBJECTIVES To evaluate the efficacy and tolerability of felbamate versus placebo when used as an add-on treatment for people with refractory partial-onset epilepsy. SEARCH METHODS We searched the Cochrane Epilepsy Group Specialized Register (24 July 2013), the Cochrane Central Register of Controlled Trials (CENTRAL 2013, Issue 6), and PubMed (24 July 2013). This search was run for the original review on 20 May 2010. There were no language and time restrictions. We reviewed the reference lists of retrieved studies to search for additional reports of relevant studies. We also contacted the manufacturers of felbamate and experts in the field for information about any unpublished or ongoing studies. SELECTION CRITERIA Randomized placebo-controlled add-on studies of people of any age with refractory partial-onset seizures. The studies could be double-blind, single-blind or unblinded and could be of parallel or crossover design. DATA COLLECTION AND ANALYSIS Two review authors independently selected studies for inclusion and extracted information. We resolved disagreements by discussion. If disagreements persisted, the third review author arbitrated. We assessed the following outcomes: 50% or greater reduction in seizure frequency; absolute or percentage reduction in seizure frequency; treatment withdrawal; adverse effects; quality of life. MAIN RESULTS Three randomised controlled trials with a total of 153 participants were included. The first was a parallel design, the second had a two-period crossover design, and the third had a three-period crossover design. One study was at unclear risk of bias for random sequence generation and allocation concealment. And in the same study, there was no description of how to blind outcome assessment, performance blinding was for participants, might not be for doctors. Two studies were at high risk of bias for incomplete outcome data. Due to significant methodological heterogeneity, clinical heterogeneity and differences in outcome measures, it was not possible to perform a meta-analysis of the results. None of the three studies reported 50% or greater reduction in seizure frequency. Only one study reported absolute and percentage reduction in seizure frequency compared to placebo, P values were 0.046 and 0.018, respectively. Adverse effects rates were higher during the felbamate period than the placebo period, particularly headache, nausea and dizziness. AUTHORS' CONCLUSIONS In view of the methodological deficiencies, limited number of individual studies and differences in outcome measure, we have found no reliable evidence to support the use of felbamate as an add-on therapy in patients with refractory partial-onset epilepsy. A large-scale, randomised controlled trial conducted over a longer period of time is required to inform clinical practice.Since the last version of this review no new studies have been found.
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Affiliation(s)
- Li Li Shi
- Nantong University Library, Evidence-based Medicine Center, Medical School of Nantong University, Nantong, China
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Abstract
BACKGROUND Partial-onset seizures contribute the bulk of seizure burden in childhood epilepsy. The therapeutic decision making involves consideration of factors specific to drug, patient and socioeconomic situation. OBJECTIVES This paper systematically reviews the available efficacy/effectiveness evidence for various anti-epileptic drugs (AED) as monotherapy and adjunctive therapy for partial-onset seizures in children. DATA SOURCES Relevant randomized clinical trials (RCTs) were identified by a structured PubMed search, supplemented by an additional hand search of reference lists and authors' files. STUDY APPRAISAL AND SYNTHESIS METHODS Eligible studies were reviewed and data extracted into tables. Included RCTs were classified based on accepted published criteria. OUTCOMES Only efficacy and effectiveness outcome measures were evaluated since there is little scientifically rigorous comprehensive AED adverse effects data. RESULTS Oxcarbazepine is the only AED with Class I evidence for efficacy/effectiveness as initial monotherapy for partial-onset seizures in children. Carbamazepine, clobazam, lamotrigine, phenobarbital, phenytoin, topiramate, valproate, vigabatrin and zonisamide have, at best, Class III efficacy/effectiveness evidence for monotherapy of partial-onset seizures in children. For adjunctive therapy, gabapentin, lamotrigine, levetiracetam, oxcarbazepine and topiramate have Class I efficacy/effectiveness evidence for treatment of pediatric partial-onset seizures. CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS This efficacy/effectiveness analysis must not be used in isolation when selecting therapy. AED selection for a specific child needs to integrate a drug's efficacy/effectiveness data with its safety and tolerability profile, pharmacokinetic properties, available formulations, and patient specific characteristics. It is critical that physicians and patients incorporate all these relevant variables when choosing AED therapy.
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Abstract
A significant number of cases of clinical canine epilepsy remain difficult to control in spite of the applied treatment. At the same time, the range of antiepileptic drugs is increasingly wide, which allows efficient treatment. In the present paper we describe the pharmacodynamics and pharmacokinetics of the newer antiepileptic drugs which were licensed after 1990 but are still not widely used in veterinary medicine. The pharmacokinetic profiles of six of these drugs were tested on dogs. The results of experimental studies suggest that second generation antiepileptic drugs may be applied in mono- as well as in poli- treatment of canine epilepsy because of the larger safety margin and more advantageous pharmacokinetic parameters. Knowledge of the drugs' pharmacokinetics allows its proper clinical appliance, which, in turn, gives the chance to improve the efficiency of pharmacotherapy of canine epilepsy.
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Li W, Stefan H, Matzen J, Rampp S, Heinze HJ, Schmitt FC. Rapid loading of intravenous lacosamide: Efficacy and practicability during presurgical video-EEG monitoring. Epilepsia 2012; 54:75-80. [DOI: 10.1111/j.1528-1167.2012.03651.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Friedman D, French JA. Clinical trials for therapeutic assessment of antiepileptic drugs in the 21st century: obstacles and solutions. Lancet Neurol 2012; 11:827-34. [DOI: 10.1016/s1474-4422(12)70177-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Abstract
BACKGROUND Epilepsy is a chronic and disabling neurologic disorder, affecting approximately one per cent of the population. Up to 30% of people with epilepsy have seizures that are resistant to currently available drugs. Felbamate is one of the second generation antiepileptic drugs and its effects as an add-on therapy to standard drugs are assessed in this review. OBJECTIVES To evaluate the efficacy and tolerability of felbamate versus placebo when used as an add-on treatment for people with refractory partial-onset epilepsy. SEARCH STRATEGY We searched the Cochrane Epilepsy Group Specialized Register (6 December 2010), the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, 6 December 2010), and PubMed (6 December 2010). There were no language restrictions. We reviewed the reference lists of retrieved studies to search for additional reports of relevant studies. We also contacted the manufacturers of felbamate and experts in the field for information about any unpublished or ongoing studies. SELECTION CRITERIA Randomized placebo-controlled add-on studies of people of any age with refractory partial-onset seizures. The studies could be double-blind, single-blind or unblinded and could be of parallel or crossover design. DATA COLLECTION AND ANALYSIS Two review authors independently selected studies for inclusion and extracted information. Disagreements were resolved by discussion. If disagreements persisted, the third review author arbitrated. The following outcomes were assessed: 50% or greater reduction in seizure frequency; absolute or percentage reduction in seizure frequency; treatment withdrawal; adverse effects; quality of life. MAIN RESULTS Three randomized controlled trials were included. The first was a parallel design, the second was a two-period crossover design, and the third was a three-period crossover design. Due to significant methodological heterogeneity, clinical heterogeneity and differences in outcome measures, it was not possible to perform a meta-analysis of the results. None of the three studies reported 50% or greater reduction in seizure frequency. Only one study reported absolute and percentage reduction in seizure frequency compared to placebo, P values were 0.046 and 0.018, respectively. Adverse effects rates were higher during the felbamate period than the placebo period, particularly headache, nausea and dizziness. AUTHORS' CONCLUSIONS In view of the methodological deficiencies, limited number of individual studies and differences in outcome measure, we have found no reliable evidence to support the use of felbamate as an add-on therapy in patients with refractory partial-onset epilepsy. A large scale, randomized controlled trial conducted over a greater period of time is required to inform clinical practice.
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Affiliation(s)
- Li Li Shi
- Nantong University Library, Evidence-based Medicine Center, Medical School of Nantong University, Nantong, China
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Zupanc ML, Roell Werner R, Schwabe MS, O'Connor SE, Marcuccilli CJ, Hecox KE, Chico MS, Eggener KA. Efficacy of felbamate in the treatment of intractable pediatric epilepsy. Pediatr Neurol 2010; 42:396-403. [PMID: 20472190 DOI: 10.1016/j.pediatrneurol.2010.02.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Revised: 09/08/2009] [Accepted: 02/11/2010] [Indexed: 01/01/2023]
Abstract
The antiepileptic drug felbamate has demonstrated efficacy against a variety of seizure types in the pediatric population, particularly seizures associated with Lennox-Gastaut syndrome. Postmarketing experience, however, revealed serious idiosyncratic adverse effects not observed during clinical trials, including aplastic anemia and liver failure. As a result, many physicians have been hesitant to prescribe felbamate. This retrospective study evaluated the efficacy of felbamate in a pediatric population with intractable epilepsy. Of 38 patients, 22 had Lennox-Gastaut syndrome (58%); 6 had myoclonic-astatic epilepsy of Doose (16%); 5 had symptomatic generalized epilepsy, not otherwise specified (13%); and 5 had symptomatic localization-related epilepsy (13%). Most patients had multiple seizure types and had been tried on a variety of antiepileptic medications. With felbamate treatment, 6 patients (16%) became seizure free, including 4 of the 6 patients with myoclonic-astatic epilepsy of Doose; 24 patients (63%) had a greater than 50% reduction in seizure frequency. In this population felbamate appeared to be safe, with minimal adverse effects. The study is limited by the small number of patients and by its retrospective nature, but nonetheless adds to the evidence that felbamate is an important antiepileptic drug for medically refractory epilepsy in children and is well tolerated with few adverse effects.
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Affiliation(s)
- Mary L Zupanc
- Department of Neurology, Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, WI, USA.
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15
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Abstract
The newer antiepileptic drugs (AEDs) provide more therapeutic options and overall improved safety and tolerability for patients. To provide the best care, physicians must be familiar with the latest tolerability and safety data. This is particularly true in children, given there are relatively fewer studies examining the effects of AEDs in children compared with adults. Since we now have significant paediatric literature on each of these agents, we provide a comprehensive and current literature review of the newer AEDs, focusing on safety and tolerability data in children and adolescents. Because the safety profiles in children differ from those in adults, familiarity with this literature is important for child neurologists and other paediatric caregivers. We have organized the data by organ system for each AED for easier reference.
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Affiliation(s)
- Dean P Sarco
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Children's Hospital Boston, Boston, Massachusetts, USA.
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17
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Abstract
Designing monotherapy trials in epilepsy is fraught with many hurdles, including diagnostic and classification difficulties, sparse information regarding the natural history of the disorder, and ethical objections to the use of placebo or a suboptimal comparator in a condition where the consequences of therapeutic failure can be serious. These issues are further complicated by regulatory differences between the US and the EU.In the US, the FDA considers that evidence of efficacy requires demonstration of superiority to a comparator. Because available antiepileptic drugs possess relatively high efficacy, in most settings it is unrealistic to expect that a new treatment will be superior to a standard treatment used at optimized dosages. To circumvent this problem, trial designs have been developed whereby patients in the control group are assigned to receive a suboptimal comparator and are required to exit from the trial if seizure deterioration occurs. This allows demonstration of a between-group difference in efficacy endpoints, such as time to exit or time to first seizure. Although these trials have come under increasing criticism because of ethical concerns, extensive information is now available on the outcome of patients with chronic epilepsy randomized to suboptimal treatment in similarly designed conversion to monotherapy trials. This has allowed the construction of a dataset of historical controls against which response to a fully active treatment can be compared. A number of studies using this novel approach are now in progress.In the EU, in addition to requiring data on conversion to monotherapy in refractory patients, the European Medicines Agency stipulates that a monotherapy indication in newly diagnosed epilepsy can only be granted if a candidate drug has shown at least a similar benefit/risk balance compared with an acknowledged standard at its optimal use during an assessment period of no less than 1 year. This has led to the implementation of noninferiority trials, one of which has been completed and which led to approval of the monotherapy indication for levetiracetam in the EU. Noninferiority trials provide valuable data in a setting that most closely resembles routine clinical practice, but their interpretation can be complicated by uncertainties on assay sensitivity.Major evidence gaps in the treatment of epilepsy still remain and it is hoped that these will be addressed in the near future. High quality monotherapy trials are particularly needed to assess the comparative efficacy of older and newer drugs in less common epilepsy syndromes, including most generalized epilepsies, and to investigate the different treatment options in populations homogeneous not only in terms of syndromic classification, but also in terms of underlying aetiology and associated phenotypes.
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Affiliation(s)
- Jacqueline A. French
- The Neurological Institute, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Steven Schachter
- Department of Neurology, Harvard Medical School, and Neurology Department, Beth Israel Deaconess Medical Center, Boston, Massachusetts, U.S.A
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Grosso S, Maria Cordelli D, Coppola G, Franzoni E, Verrotti A, Berardi R, Balestri P. Efficacy and safety of felbamate in children under 4 years of age: a retrospective chart review. Eur J Neurol 2008; 15:940-6. [DOI: 10.1111/j.1468-1331.2008.02215.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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21
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Abstract
The incidence of refractory seizures has remained at 30-40%, even with the approval of nine new anticonvulsants over the past 12 years. In attempts to reduce seizure frequency and severity, physicians routinely resort to combining two or more anticonvulsants, ideally with different mechanisms of action. These combinatorial therapies are difficult to administer for both patient and caregiver and often result in tolerability issues. Hence, a broad spectrum anticonvulsant, with multiple mechanisms of action, that is well tolerated, would provide physicians with an important option in their armamentarium to control seizures. Felbamate initially fit this profile and was demonstrated to effectively control both partial and generalized seizures in clinical studies supporting registration. Unfortunately, unanticipated idiosyncratic toxicity was observed after approval and the drug is now relegated to second or third line therapy, depending on patient history and seizure type. Epileptologists still prescribe this drug for refractory seizures, and a recent communication indicates that 35,000 to 46,000 new patients have tried Felbatol (MedPointe Pharmaceuticals, Somerset, NJ) since 1995. The continued utilization of Felbatol, in light of its risk:benefit issues, highlights the need for new efficacious therapeutic options. Fluorofelbamate (MedPointe Pharmaceuticals), a phase I drug candidate, was designed to retain the broad spectrum multimechanistic activity of felbamate, with a modified metabolism that has demonstrated, in vitro, to avoid the production of the reactive metabolite believed to cause the idiosyncratic toxicity. This drug candidate is one of several carbamates either in development or currently on the market for treatment of seizures and other CNS disorders.
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22
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Bialer M, Johannessen SI, Kupferberg HJ, Levy RH, Perucca E, Tomson T. Progress report on new antiepileptic drugs: a summary of the Eigth Eilat Conference (EILAT VIII). Epilepsy Res 2006; 73:1-52. [PMID: 17158031 DOI: 10.1016/j.eplepsyres.2006.10.008] [Citation(s) in RCA: 220] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2006] [Accepted: 10/30/2006] [Indexed: 12/15/2022]
Abstract
The Eigth Eilat Conference on New Antiepileptic Drugs (AEDs)-EILAT VII, took place in Sitges, Barcelona from the 10th to 14th September, 2006. Basic scientists, clinical pharmacologists and neurologists from 24 countries attended the conference, whose main themes included a focus on status epilepticus (epidemiology, current and future treatments), evidence-based treatment guidelines and the potential of neurostimulation in refractory epilepsy. Consistent with previous formats of this conference, the central part of the conference was devoted to a review of AEDs in development, as well as updates on marketed AEDs introduced since 1989. This article summarizes the information presented on drugs in development, including brivaracetam, eslicarbazepine acetate (BIA-2-093), fluorofelbamate, ganaxolone, huperzine, lacosamide, retigabine, rufinamide, seletracetam, stiripentol, talampanel, valrocemide, JZP-4, NS1209, PID and RWJ-333369. Updates on felbamate, gabapentin, lamotrigine, levetiracetam, oxcarbazepine and new extended release oxcarbazepine formulations, pregabalin, tiagabine, topiramate, vigabatrin, zonisamide and new extended release valproic acid formulations, and the antiepileptic vagal stimulator device are also presented.
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Affiliation(s)
- Meir Bialer
- Department of Pharmaceutics, School of Pharmacy, David R. Bloom Center for Pharmacy, The Hebrew University of Jerusalem, 91120 Jerusalem, Israel.
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23
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Pellock JM, Faught E, Leppik IE, Shinnar S, Zupanc ML. Felbamate: Consensus of current clinical experience. Epilepsy Res 2006; 71:89-101. [PMID: 16889941 DOI: 10.1016/j.eplepsyres.2006.06.020] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2006] [Accepted: 06/22/2006] [Indexed: 11/25/2022]
Abstract
An expert panel convened to evaluate data and review current clinical practices regarding the novel antiepileptic drug (AED) felbamate. Felbamate has demonstrated efficacy against a variety of refractory seizures types, including seizures associated with Lennox-Gastaut syndrome, but postmarketing experience revealed serious idiosyncratic adverse effects that were not observed during clinical trials. Although felbamate is not indicated as first-line antiepileptic therapy, its utility in treating seizures that are refractory to other AEDs is undisputed, as shown by the number of patients who continue to use it. New exposures to felbamate number approximately 3200-4200 patients annually, and it is estimated that over the past 10 years, approximately 35,000 new starts have occurred. Recommendations by the American Academy of Neurology and a review of felbamate literature were evaluated in conjunction with the clinical experience of the expert panel to determine current medical opinion and practice regarding felbamate. The past 10 years of clinical experience have demonstrated that when used in accordance with existing recommendations and close clinical monitoring, felbamate is an effective treatment for some patients with seizures refractory to other AEDs. This review of clinical data and discussion of the current understanding of the risk:benefit of felbamate therapy supports its use as an important therapeutic option for some patients with refractory epilepsy.
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Affiliation(s)
- John M Pellock
- Virginia Commonwealth University, Medical College of Virginia, PO Box 980211, 1001 E. Marshall St., 1st floor, Richmond, VA 23298, USA.
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24
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Bialer M, Johannessen SI, Kupferberg HJ, Levy RH, Perucca E, Tomson T. Progress report on new antiepileptic drugs: a summary of the Seventh Eilat Conference (EILAT VII). Epilepsy Res 2004; 61:1-48. [PMID: 15570674 DOI: 10.1016/j.eplepsyres.2004.07.010] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The Seventh Eilat Conference on New Antiepileptic Drugs (AEDs) (EILAT VII) took place in Villasimius, Sardinia, Italy from the 9th to 13th May 2004. Basic scientists, clinical pharmacologists and neurologists from 24 countries attended the conference,whose main themes included advances in pathophysiology of drug resistance, new AEDs in pediatric epilepsy syndromes, modes of AED action and spectrum of adverse effects and a re-appraisal of comparative responses to AED combinations. Consistent with previous formats of this conference, the central part of the conference was devoted to a review of AEDs in development, as well as updates on second-generation AEDs. This article summarizes the information presented on drugs in development, including atipamezole, BIA-2-093, fluorofelbamate, NPS 1776, pregabalin, retigabine, safinamide, SPM 927, stiripentol, talampanel,ucb 34714 and valrocemide (TV 1901). Updates on felbamate, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, tiagabine,topiramate, vigabatrin, zonisamide, new oral and parenteral formulations of valproic acid and SPM 927 and the antiepileptic vagal stimulator device are also presented.
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Affiliation(s)
- Meir Bialer
- Department of Pharmaceutics, Faculty of Medicine, School of Pharmacy and David R. Bloom Center for Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel.
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25
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Abstract
The new onset of epilepsy usually leads to initiation of treatment with antiepileptic drugs (AEDs). Selection of the appropriate drug in this clinical situation is usually based on several factors, including efficacy for the suspected epilepsy type, tolerability, acute and long-term idiosyncratic side effects, pharmacokinetic interactions, possibility of rapid titration, formulation, and expense. Over the last several years, the choices for treatment in newly diagnosed epilepsy have increased because a number of new AEDs have been approved for use in monotherapy. This article reviews randomized, controlled studies that have evaluated the use of new AEDs in monotherapy.
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Affiliation(s)
- Antonio Gil-Nagel
- Servicio de Neurología, Programa de Epilepsia, Hospital Ruber Internacional, Madrid, Spain.
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26
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Abstract
Although antiepileptic drugs (AEDs) are commonly used to control and prevent seizures, their long-term use carries a considerable risk of morbidity. The decision to start AEDs is made once the risks of further seizures outweigh the risks of treatment. Despite a large body of literature on the subject, this common clinical issue perplexes many practitioners because of its neurologic, psychological, and, at times, legal implications. Adding to the confusion is the recent approval of several new AEDs. This article summarizes the current evidence to support individual clinical decisions regarding initiation of AEDs in adults and considers the use of AEDs as seizure prophylaxis. Recently approved AEDs are discussed to help the practitioner understand when to initiate and how to choose the appropriate AED for the patient with seizures.
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27
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Devinsky O, Vazquez B, Faught E, Leppik IE, Pellock JM, Schachter S, Alderfer V, Holdich TAH. A double-blind, placebo-controlled study of remacemide hydrochloride in patients with refractory epilepsy following pre-surgical assessment. Seizure 2002; 11:371-6. [PMID: 12160664 DOI: 10.1053/seiz.2001.0669] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
This multicentre, randomised, double-blind, placebo-controlled, parallel-group study investigated the efficacy, safety and pharmacokinetics of remacemide hydrochloride in adult patients ( n= 59) with refractory epilepsy, undergoing reduced or discontinued antiepileptic drug (AED) usage, as part of an evaluation for epilepsy surgery. On discontinuation or reduction of maintenance AEDs, patients received remacemide hydrochloride, up to 600 mg daily, or placebo, for up to ten days or until they experienced a fourth complex partial (CPS) or a generalised tonic-clonic (GTC) seizure. Pre- and post-study blood and urine samples were taken for analysis. Remacemide hydrochloride showed a significantly ( P= 0.045) longer median time to fourth seizure compared with placebo (6.8 vs. 3.8 days). Median nine-day seizure counts were significantly ( P= 0.0327) lower with remacemide hydrochloride than placebo (6.2 vs. 12.8). Eleven remacemide hydrochloride patients and six placebo patients completed ten days' treatment. Remacemide and desglycinyl metabolite levels were lower in patients receiving concomitant carbamazepine or phenytoin than in those receiving non-inducing AEDs or remacemide hydrochloride alone. No serious adverse events occurred; all patients receiving remacemide hydrochloride completed the study. Remacemide hydrochloride was well tolerated and showed significant therapeutic activity in this patient population.
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Affiliation(s)
- O Devinsky
- New York Hospital for Joint Diseases, New York, USA
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28
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Leach JP, Marson T, Chadwick D. New Antiepileptic Drugs Revolution or Marketing Spin? Pract Neurol 2001. [DOI: 10.1046/j.1474-7766.2001.00002.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Cilio MR, Kartashov AI, Vigevano F. The long-term use of felbamate in children with severe refractory epilepsy. Epilepsy Res 2001; 47:1-7. [PMID: 11673015 DOI: 10.1016/s0920-1211(01)00290-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The aim of the study was to assess the efficacy and safety of felbamate (FBM) as add-on therapy in pediatric patients with severe uncontrolled seizures during a 3-year follow-up. Thirty-six patients were enrolled between February 1994 and February 1997. Patients suffered from partial epilepsy (n=13), Lennox-Gastaut syndrome (LGS) (n=9), infantile spasms (IS) n=8 or other forms of generalized epilepsy (n=6). FBM was titrated weekly from 15 up to 45 mg/kg. By February 1995, all patients had hematological and biochemical monitoring prior to FBM therapy and every 15 days during the study. The results achieved at different treatment durations were analyzed. Overall efficacy measured as > or =50% reduction in seizure frequency varied during follow-up: 69% at 3 months, progressively decreasing to 66% at 6 months, to 47% at 1 year and 41% of the initial cohort at the end of the study. Most frequent side effects were anorexia, weight loss, urinary retention, somnolence, nervousness and insomnia. FBM controlled a broad spectrum of otherwise refractory seizures. Best results were obtained against simple partial seizures with or without secondary generalization, tonic and atonic seizures. A substantial improvement in seizure control was maintained in one-third of the patients for at least 3 years.
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Affiliation(s)
- M R Cilio
- Division of Neurology, Bambino Gesú Children's Hospital, Rome, Italy.
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30
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Schwabe S. Inpatient monotherapy studies in epilepsy: pro. Epilepsy Behav 2001; 2:327-9. [PMID: 12609208 DOI: 10.1006/ebeh.2001.0228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2001] [Accepted: 06/15/2001] [Indexed: 11/22/2022]
Affiliation(s)
- S Schwabe
- The R. W. Johnson Pharmaceutical Research Institute, 920 U.S. Route 202, PO Box 300, Raritan, New Jersey, 08869-0602
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31
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Ruehlmann D, Podell M, March P. Treatment of partial seizures and seizure-like activity with felbamate in six dogs. J Small Anim Pract 2001; 42:403-8. [PMID: 11518421 DOI: 10.1111/j.1748-5827.2001.tb02490.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Six dogs with partial seizures or partial seizure-like activity were treated with the antiepileptic drug felbamate between 1993 and 1998. All dogs had a history and results of diagnostic testing suggestive of either primary (idiopathic) or occult secondary epilepsy. Dogs ranged between four months and eight years of age at the onset of seizure activity. The median time period between onset of the first seizure and the start of felbamate therapy was 3.8 months (range 0.75 to 36 months). Median duration of therapy was nine months (range two to 22 months). All dogs experienced a reduction in seizure frequency after felbamate administration. Median total number of seizures post-treatment was two (range 0 to 9). Two dogs had an immediate and prolonged cessation of seizure activity. Steady-state trough serum felbamate concentrations measured at two weeks, and one, 12 and 22 months after the commencement of therapy in four dogs ranged between 13 and 55 mg/litre (median 35 mg/litre). Reversible haematological adverse effects were detected in two dogs, with one dog developing concurrent keratoconjunctivitis sicca. These results suggest that felbamate can be an effective antiepileptic drug without life-threatening complications when used as monotherapy for partial seizures in the dog.
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Affiliation(s)
- D Ruehlmann
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus 43210, USA
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Chadwick D. Inpatient monotherapy studies in epilepsy: con. Epilepsy Behav 2001; 2:324-6. [PMID: 12609207 DOI: 10.1006/ebeh.2001.0227] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2001] [Accepted: 06/15/2001] [Indexed: 11/22/2022]
Affiliation(s)
- D Chadwick
- Walton Centre for Neurology and Neurosurgery, Department of Neurological Science, University of Liverpool, Lower Lane, Fazakerley, Liverpool, L9 7LJ, United Kingdom
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Abstract
OBJECTIVE To review the epidemiology and pharmacologic management of epilepsy in elderly patients. DATA SOURCES Controlled trials, case studies, and review articles identified via MEDLINE using the search terms epilepsy, seizures, elderly, phenobarbital, primidone, phenytoin, carbamazepine, valproic acid, felbamate, gabapentin, lamotrigine, topiramate, tiagabine, levetiracetam, oxcarbazepine, and zonisamide. Recently published standard textbooks on epilepsy were also consulted. DATA SYNTHESIS Epilepsy is a common neurologic disorder in the elderly. Cerebrovascular and neurodegenerative diseases are the most common causes of new-onset seizures in these patients. Alterations in protein binding, distribution, elimination, and increased sensitivity to the pharmacodynamic effects of antiepileptic drugs (AEDs) are relatively frequent, and these factors should be assessed at the initiation, and during adjustment, of treatment. Drug-drug interactions are also an important issue in elderly patients, because multiple drug use is common and AEDs are susceptible to many interactions. In addition to understanding age-related changes in the pharmacokinetics and pharmacodynamics of AEDs, clinicians should know the common seizure types in the elderly and the spectrum of AED activity for these seizure types. AEDs with activity against both partial-onset and generalized seizures include felbamate, lamotrigine, levetiracetam, topiramate, valproic acid, and zonisamide. Other AEDs discussed in this review (carbamazepine, gabapentin, phenobarbital, phenytoin, primidone, and tiagabine) are most useful for partial-onset seizures. CONCLUSION The provision of safe and effective drug therapy to elderly patients requires an understanding of the unique age-related changes' in the pharmacokinetics and pharmacodynamics of AEDs as well as an appreciation of common seizure types and the drugs that are effective for the specific types seen in the elderly.
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Affiliation(s)
- S V Bourdet
- University of North Carolina Hospitals, Chapel Hill, USA
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34
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Abstract
Monotherapy antiepileptic drug (AED) trials can optimally provide information concerning efficacy and tolerability of one drug compared with placebo, as well as to different doses or rates of administration. Commonly, a drug is compared with one or more other drugs. The outcome measures will be dictated by the questions being asked. In most comparative studies, the single overall result that best defines success or failure is time of continuation on drug as expressed in a life table. Discontinuation before planned completion of the study implies insufficient efficacy or unacceptable adverse effects. A statistically significant difference between treatments provides important support for recommending the drug or dose with the best outcome. The criteria for continuation/discontinuation are defined in the design based on the expected outcome. The outcome of primary importance is efficacy in prevention of seizures or a decrease in severity. Complete control for the duration of the study is the ultimate goal but in some populations may not be possible. The number of subjects entering remission gives further information about long term outcome. Time to first (nth) seizure provides similar evidence of efficacy. Seizure rates allow comparisons of subjects retained for different lengths of time in the trial. Differences in seizure severity may be of clinical importance and multiple efforts have been made to develop instruments to accurately measure this outcome. Adverse effects of the drugs are the second major outcome. These can be expressed as incidence and/or prevalence. The presence and frequency of side effects will depend on how the study is designed and whether these effects are specifically sought by the investigators. Serious systemic safety outcomes are monitored, but the relative infrequency of occurrence and number of subjects in the trials usually do not provide enough power to detect statistically significant differences except for rash. Tolerability is more easily documented but is difficult to access accurately in the absence of placebo controls. Frequency, severity and persistence are measurable. Specific unwanted types of drug effects can be specifically studied using detailed neuropsychological test batteries. Some information concerning pharmacokinetic properties may be obtained but are better assessed in other types of trials. A final important outcome is the effect of drug therapy on quality of life. Although a favorable finding in this outcome is most desirable, the measures used are much less precise than those for efficacy and adverse effects.
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Affiliation(s)
- R H Mattson
- Department of Neurology, Yale University, 333 Cedar Street, 701 LCI, New Haven, CT 06510, USA.
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35
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Abstract
Presurgical evaluation of patients with refractory partial seizures provides a unique opportunity to perform a placebo-controlled, monotherapy trial. Some patients undergoing presurgical evaluations must have all of their antiepileptic drugs (AEDs) tapered in order to induce seizures and therefore such patients are possible candidates for a placebo-controlled monotherapy trial. Often, EEG monitoring is continued throughout the trial period, thus patients either receiving placebo or whose seizures do not completely respond to the active drug are still evaluated to determine whether or not surgery is feasible, supporting the validity of a trial in this setting. In addition, all patients are, in general, eligible to receive the study drug after the blinded period of the trial, and can therefore be assured of the possible therapeutic benefits of the study. Presurgical inpatients studies have been carried out using felbamate, gabapentin and oxcarbazepine. All patients randomised in these trials were refractory to previous treatment and the studies themselves were short-term and placebo-controlled. These presurgical studies are designed to elucidate AED activity and show statistically significant differences between active and control treatments during short-term therapy, and are therefore of use in fulfilling regulatory requirements. However, these measures of efficacy are distinctly different from those determined during chronic treatment and are therefore not necessarily predictive of clinical usefulness.
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Affiliation(s)
- G Pledger
- RW Johnson Pharmaceutical Research Institute, 929 Route 202, South Raritan, NJ 9202, USA.
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36
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Ben-Menachem E, Falter U. Efficacy and tolerability of levetiracetam 3000 mg/d in patients with refractory partial seizures: a multicenter, double-blind, responder-selected study evaluating monotherapy. European Levetiracetam Study Group. Epilepsia 2000; 41:1276-83. [PMID: 11051122 DOI: 10.1111/j.1528-1157.2000.tb04605.x] [Citation(s) in RCA: 284] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE To evaluate the efficacy and tolerability of levetiracetam (LEV) monotherapy in selected patients with refractory partial seizures. METHODS In this multicenter, double-blind, placebo-controlled, parallel-group, responder-selected study, patients were randomized (2:1 ratio) to receive oral LEV 1500 mg twice daily or placebo during a 12-week add-on phase. Treatment responders (patients with a reduction in partial seizure frequency of 50% or more compared with baseline) entered a monotherapy phase that included a maximum 12-week down-titration period and 12 weeks of monotherapy at 1500 mg twice daily. In both phases, responder rate, seizure frequency, and adverse events were analyzed. RESULTS A total of 286 patients (placebo, n = 105; LEV, n = 181) entered the add-on phase, and 86 patients (placebo, n = 17; LEV, n = 69) were eligible for the monotherapy phase. Thirty-six of 181 patients (19.9%) who received LEV completed the entire study compared with only 10 of 105 patients (9.5%) in the placebo group (p = 0.029). The odds of completing the study on LEV were 2.36 times (95% confidence interval, 1.08, 5.57) higher than on placebo. The responder rate during the add-on phase was significantly higher in the LEV group compared with the placebo group (42.1% vs. 16.7%, respectively; p < 0.001). In the LEV monotherapy group, the median percent reduction in partial seizure frequency compared with baseline was 73.8% (p = 0.037), with a responder rate of 59.2%. Nine patients (18.4%) remained seizure-free on LEV monotherapy. CONCLUSIONS Conversion to LEV monotherapy (1500 mg twice daily) is effective and well tolerated in patients with refractory partial seizures who responded to 3000 mg/d LEV as add-on therapy.
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Affiliation(s)
- E Ben-Menachem
- Department of Clinical Neuroscience, Sahlgrenska, University Hospital, Göteborg, Sweden.
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37
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Abstract
Treatment options for epilepsy have increased markedly since 1990, when only carbamazepine, phenytoin, phenobarbital, primidone, and valproate were used commonly for partial and secondarily generalized seizures. Those with primary generalized seizures received ethosuximide or valproate. Over the past decade, however, additional agents have been introduced, with the promise of improved seizure control and minimal side effects. The new antiepileptic drugs (AEDs)-felbamate, gabapentin, lamotrigine, tiagabine, topiramate, vigabatrin and oxcarbazepine-have demonstrated superior efficacy for some with refractory epilepsy. In addition, the new agents frequently are better tolerated when used as monotherapy or adjunctive therapy. The optimal place for the new AED will require additional studies and careful postmarketing surveillance and assessments. Although these AEDs offer benefits, not all patients with epilepsy have responded. Thus, the search for new AEDs continues.
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Affiliation(s)
- J M Pellock
- Division of Child Neurology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0211, USA
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38
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Abstract
Prior to 1993, there were only six major drugs available in the US for the treatment of patients with epilepsy. These included phenobarbital (PB), phenytoin (PHT), carbamazepine (CBZ), primidone (PRIM), valproic acid/sodium valproate (VPA) and ethosuximide (ESX). Of these drugs, VPA has the broadest spectrum of activity and ESX the most limited. Despite these six agents, as well as several secondary drugs, it is estimated that over 30% of patients have inadequate seizure control, while others, whose disease is adequately controlled, suffer from bothersome adverse events (AEs). Since 1993, ten new drugs have entered the worldwide market (not all in the US). Those released include felbamate (FBM), gabapentin (GBP), lamotrigine (LTG), topiramate (TPM), tiagabine (TGB), oxcarbazepine (OXC), levetiracetam (LVT), zonisamide (ZNS), clobazam (CLB) and vigabatrin (VGB). The purpose of this article is to review each of the above drugs, looking at efficacy, safety, tolerability and where they may play a role in the current treatment of epilepsy.
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Affiliation(s)
- P H McCabe
- Adult Comprehensive Epilepsy Treatment Center, Milton S Hershey Medical Center, Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA 17033, USA.
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Wiebe S. Seizure control as an indicator of therapeutic usefulness. Can J Neurol Sci 2000; 27 Suppl 1:S97-105; discussion S121-5. [PMID: 10830335 DOI: 10.1017/s0317167100000743] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Seizure control, in addition to quality of life, is an important outcome after epilepsy surgery. However, seizure measurement is not straightforward. We explore some important difficulties in obtaining unbiased, reliable estimates of seizure frequency, and discuss aspects of data analysis as it pertains to validity and clinical meaningfulness. As seizure severity is an integral component of seizure outcome assessment, we discuss aspects of measurement of this outcome. Suggestions for improving validity are offered, based on the literature and on methodological common sense. Finally, we look at the Canadian perspective and the potential for adopting methodology that allows for data pooling and for more powerful analyses.
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Affiliation(s)
- S Wiebe
- Department of Clinical Neurological Sciences, University of Western Ontario, London, Canada
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40
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Abstract
Until 1993, carbamazepine (CBZ), phenytoin (PHT), phenobarbital (PB), and valproate (VPA) accounted for the great majority of the prescriptions written for the treatment of epilepsy. Since 1993, five antiepileptic drugs (AEDs) have been released in the United States, and at least three additional drugs are expected to be released by the end of the year 2000. As a group, these newer drugs differ from the established drugs in terms of their pharmacokinetics, interaction potential, and adverse effects. In addition, any one of the newer drugs may achieve seizure control in situations in which an established drug had not. The newer drugs certainly represent a welcome addition to the existing options for the treatment of epilepsy in children. However, the availability of several new AEDs represents a therapeutic dilemma for the clinician because optimal use of these drugs has not yet been established. This is particularly true in children because (i) newer drugs are often studied less frequently in children, (ii) pharmacokinetics in children differ from those in adults, (iii) children may have different adverse effects, and (iv) children have a broader spectrum of various seizure types and epilepsy syndromes. In the first part of this review, the clinical pharmacology of the currently available newer AEDs is discussed individually, with special emphasis on data in children. In particular, pharmacokinetics, interactions, dosage and titration, efficacy spectrum, and adverse effect profile is discussed for each drug. In the second part, an attempt is made to determine the place for the newer drugs in the treatment of the different pediatric seizures and epilepsy syndromes.
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Affiliation(s)
- B F Bourgeois
- Department of Neurology, Harvard Medical School, Boston, Massachusetts, USA
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41
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Affiliation(s)
- F J Vajda
- Australian Centre for Clinical Neuropharmacology, St. Vincent's Hospital, Fitzroy, Victoria
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42
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Abstract
The management of epilepsy in the pediatric patient requires careful evaluation, classification, and pharmacologic treatment. Despite best efforts on the part of clinicians, approximately 25% of children remain refractory to appropriate medical therapies. The development of an improved classification system and the emergence of several new antiepileptic drugs have enabled some progress in this area, specifically in children with disorders such as Lennox-Gastaut syndrome and infantile spasms, which are notoriously difficult to control. However, limited data are available that define the optimal use of new antiepileptic agents in pediatric patients. To most effectively treat children with epilepsy syndromes, further research must be completed to validate the positive effects described in case reports, open-label clinical trials, and early controlled clinical trials.
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Affiliation(s)
- J M Pellock
- Division of Child Neurology, Medical College of Virginia of Virginia Commonwealth University, Richmond, Virginia 23298-0211, USA.
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43
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Pellock JM, Appleton R. Use of new antiepileptic drugs in the treatment of childhood epilepsy. Epilepsia 1999; 40 Suppl 6:S29-38; discussion S73-4. [PMID: 10530681 DOI: 10.1111/j.1528-1157.1999.tb00931.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The management of epilepsy in children requires careful evaluation, classification, and pharmacologic treatment. With classic antiepileptic drugs (AEDs), at least 25% of children remain refractory to appropriate therapy. The past decade has allowed the introduction of a number of newer AEDs for treatment of both adults and children with epilepsy. These include felbamate, gabapentin, lamotrigine, topiramate, tiagabine, and vigabatrin. Emerging information regarding the efficacy of these AEDs in treating childhood epilepsy syndromes suggests advantages for many patients. Limited data are available that define the optimal use of new AEDs in pediatric patients. Further research must be completed to validate the positive effects described in existing clinical trials of the new AEDs in the treatment of childhood epilepsy.
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Affiliation(s)
- J M Pellock
- Division of Child Neurology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0211, USA
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44
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Abstract
Felbamate (FBM) was the first of the new antiepileptic drugs (AEDs) approved in the United States in 1993 with broad-spectrum efficacy against partial and generalized seizures of various types, and indicated for use as adjunctive and monotherapy. The identification of idiosyncratic aplastic anemia and hepatotoxicity, however, drastically curtailed its use. To update information concerning FBM and its idiosyncratic effects, case studies and literature reviews were undertaken. Thirty-four FBM-associated aplastic anemia patients have been reported, with 13 known fatalities. The overall FBM aplastic anemia risk is estimated at between 27 and 209 per million vs. 2 to 2.5 per million in the general population. Prior AED hypersensitivity, cytopenia, and immune disease significantly increase risk. FBM aplastic anemia has not been reported in children below the age of 13 years. Hepatic failure is much less common, occurring with an overall risk similar to that associated with valproate, but children below the age of 5 years have been affected. The recent identification of a reactive metabolite, atropaldehyde, and HLA studies suggest that high-risk patients can be identified. The efficacy profile of FBM should encourage further investigations to allow its better use, but at present FBM is not a first-line AED.
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Affiliation(s)
- J M Pellock
- Department of Neurology, Medical College of Virginia of Virginia Commonwealth University, Richmond 23298-0211, USA
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45
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Abstract
Management of epilepsy in the elderly involves many challenges, including the presence of concomitant diseases, polypharmacy and changes in body physiology. Age-related changes in pharmacokinetics and pharmacodynamics have to be taken into account in order to avoid potentially severe adverse drug reactions in elderly people. The present study reviews the most commonly used antiepileptic drugs (AEDs) in the elderly. Because some AEDs may induce the metabolism of other agents and reduce the effectiveness of several drugs, the physicians have to carefully evaluate concomitant drugs being administered. Moreover, the main problems appear to be when beginning therapy, the first choice drug, the appropriate dosage and pharmacologic compliance. Elderly patients must be screened for hepatic and renal functions before beginning a treatment with an AED, carefully interviewed to reduce complaints for drug side-effects which may negatively influence compliance and monitored for total and free blood levels. Besides the 'classic' AEDs, such as phenytoin, phenobarbital, carbamazepine, valproic acid, primidone and benzodiazepines, the review shows the possible advantages of new AEDs, such as felbamate, gabapentin, lamotrigine, oxcarbazepine and gamma-vinyl-GABA, which may be used in the elderly too for their good tolerability. A careful control of drug assumption is requested in the elderly, especially when it is difficult to achieve seizure control.
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Affiliation(s)
- P Gareri
- Department of Clinical and Experimental Medicine, University of Catanzaro, Italy
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46
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French J, Smith M, Faught E, Brown L. Practice Advisory: The Use of Felbamate in the Treatment of Patients with Intractable Epilepsy. Report of the Quality Standards Subcommittee of the American Academy of Neurology and the American Epilepsy Society. Epilepsia 1999. [DOI: 10.1111/j.1528-1157.1999.tb00784.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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47
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French J, Smith M, Faught E, Brown L. Practice advisory: The use of felbamate in the treatment of patients with intractable epilepsy: report of the Quality Standards Subcommittee of the American Academy of Neurology and the American Epilepsy Society. Neurology 1999; 52:1540-5. [PMID: 10331676 DOI: 10.1212/wnl.52.8.1540] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- J French
- American Academy of Neurology, St. Paul, MN 55116, USA
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48
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Meythaler JM, Yablon SA. Antiepileptic Drugs. Phys Med Rehabil Clin N Am 1999. [DOI: 10.1016/s1047-9651(18)30197-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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49
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50
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Abstract
This open-label study was performed to evaluate efficacy and safety of Felbamate (FBM) add-on therapy in drug-refractory partial epilepsy. We evaluated 36 patients (12 males) aged 11-68 years (mean 29.8) in which FBM was titrated gradually from 300 mg/day to a mean total maintenance daily dose of 1936 mg. Patients were monitored according to clinical practice and performed regularly laboratory tests. Mean follow-up of FBM therapy was 10 months (range 2-27). In this study, 5% of patients resulted to be seizure-free, 11% showed a seizure reduction more than 75%, 23% decreased their seizure frequency between 50% and 75% (P = 0.0001). The adverse events which were reported more frequently were: nausea, vomiting, anorexia and weight loss. Even if the patients sample is small FBM proves its efficacy in partial epilepsy, showing a relatively well tolerated profile.
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Affiliation(s)
- R Canger
- Epilepsy Regional Centre, San Paolo Hospital, University of Milan, School of Medicine, Italy.
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